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Home , Cheek teeth, Cynodont, Cynognathus, Diademodontidae, Mammal, Massetognathus

71

Palaeont. afr., 14.71-85.1972

A REVISED CLASSIFICATION OF (REPTILIA; THERAPSIDA)

by

* James A. Hopson and tJames W. Kitching

INTRODUCTION We wish to thank the following colleagues for Cynodonts are very advanced -like access to unpublished information which has been incorpo~ated ~nto th~s ~eptiles of the Pe:m<;>- which are of special paper: Dr. J. F. Bonaparte, Interest to evolutIOnIsts because they gave rise to FundacIOn MIgUel LIllo, Tucuman, ; Dr. t~e Mammalia during Middle or A. W. Crompton, Museum of Comparative tIme. Cynodonts have been known from strata of , Har~' ard University; and Mr. J. W. A. van age in for over one Heerden, NatIOnal Museum, Bloemfontein. hundred years, and numerous specimens have been Several aspect~ .of this classification require collected and described. In recent years the record comment. In deCIdIng whether to consider a of cynodonts has been extended into earlier and generic or specific name to be valid, we have taken later time zones, not only in southern Africa but the ~osition that. the burden of proof is on the in East Africa, South America, , China' , and , descnber to conVInce us that the named taxon is most recently, in North America. Much of the distinct from earlier-named taxa. Where there is a material from outside of Africa has not yet been reasonably high probability that two named taxa fully described. are synonymous, we have usually synonymized . Ap'prox~m~tely 125 of cynodonts them, even though the evidence for their identity is (Includmg IctIdosaurs and tritylodonts herein not conclusive. We have done this because: (1) the considered to be cynodonts) have been n~med. Of cynodonts have been excessively split (as, in fact, these, however, only a very small handful has been ha~e . most groups), so that our first adequately characterized so that anyone species pnonty seemed to be the reduction of the can be reliably distinguished from all others. As a confusing welter of inadequately-characterized result of the taxonomic confusion which prevails in gen~ra and species to fewer, more adequately defIned taxa; (2) many of the type specimens are the Cy:nodo~ti~, our knowledge of the patterns of wIthm the group is based on detailed f:agmentary and poorly-preserved so that diagnos­ knowledge of a few species. tIC ~harac~ers are lackIng; (3) where locality and . The stimulus for the present revised classifica­ stratIgraphIc data are available, it is evident that an tIOn of cynodonts was an extended research visit to excessive number of closely-related species have the Bernard Price Institute for Palaeontological been na!ll~d from very limited geographic areas and Research by the senior author in late 1971. The from wIthIn very narrow stratigraphic intervals. In purpose of the visit was to study primitive those cases where taxa based on inadequate types cy?odonts, but all available material in could be reasonably synonymized with adequately­ thIS and many other South African museums was characterized species, we did so but where examined. tt The junior author has also studied most inadequate types could not be so allo~ated we have of th.e .cynodont mate:ial in South Africa as part of chosen to declare the names on which they are a reVISIOn of the stratIgraphy and fauna based to be nomina vana. of · the Beaufort Series. Many of the taxonomic . The highe~-level classification adopted here dIffers substantIally from that used in most earlier conclusions independently reached by the two classifications (e.g., Watson and Romer, 1956; ' ~uthors have proven to be identical, though based In great part on different evidence. Because of the Romer, 1966; Lehman, 1961; but see Haughton ~nd Bri~k, 1954). We have abandoned separate larg~ amount of overlap in our work, we have decIded to publish our taxonomic conclusions as a In~raordInal . rank for the "Ictidosauria" (i.e., TntheledontIdae) and ; instead joint report, ~eserving for separate future papers the presentatIOn of the detailed evidence upon they are listed as families within the Infraorder which these conclusions are based. For the sake of Cy~od(:mtia. These groups are clearly cynodont completeness, the senior author has reviewed the denvatIves and we believe that their positions as non-Sout~ A.frican cynodonts, though many of the * James A. Hopson, The University of Chicago, Department of taxonomIC Judgments on these forms are less , 1025 East 57th Street, Chicago, Illinois 60637, U.S.A. securely b~sed than are the judgments on the t Jam.es W. Kitching, University of the , Bernard Price South Afncan cynodonts. The revision of the InstItute for Palaeontological Research, Milner Park, Johannes­ burg, South Africa. Tritylodontidae is based on the senior tt This research was supported by a grant from the National author's unpublished studies. Science Foundation. 72 advanced end-members of two major adaptive lines genera, and and (2) within the cynodont radiation are best indicated the fact that these genera represent extremes of by incorporating them within the Cynodontia. specialization within their respective groups. The Their respective positions as the culmination of the resulting classification, we believe, possesses the carnivorous and herbivorous rami of the cynodonts advantage of expressing both phyletic relationships has been expressed in the classification by dividing and adaptive trends better than those classifica­ the infraorder into two main groups at the level of tions which place the cynodonts and their superfamily. For the carnivorous group, we have therapsid descendants in three infraorders (Cyno­ adopted Brink's (1963) term Cynognathoidea; for dontia, Ictidosauria, and Tritylodontia). A similar the herbivorous group, we have chosen to use sort of reclassification of other therapsid groups, Simpson's (1928) term Tritylodontoidea. These notably of the therocephalian-bauriamorph choices were determined by: (1) familiarity of the assemblage, is also overdue.

INFRAORDER CYNODONTIA SUPERFAMILY CYNOGNATHOIDEA Brink 1963. Cynodonts in which the posterior postcanine teeth usually possess three or more cusps aligned in an anteroposterior row; a narrow lingual cingulum bearing several small cusps is frequently present, but only rarely is the cingulum expanded to form a broad lingual shelf; canines are usually well-developed; are usually small and unspecialized. Most members are carnivorous. Included are primitive cynodonts of the and earliest Triassic and all carnivorous cynodonts of the later Triassic.

FAMILY PROCYNOSUCHIDAE Broom 1948. Includes: Silphedestidae Haughton and Brink 1954; Dviniidae Tatarinov 1968 a. Primitive cynodonts with five or more incisors, small "precanine" maxillary' teeth in front of the enlarged canine, and posterior postcanine teeth with a prominent lingual cingulum; the dentary is small, with a low coronoid process, no angle, and with the masseteric restricted to the posterodorsal portion of the bone; palatal plates of the maxillae and palatines do not meet at the midline so that the secondary is incomplete; interpterygoidal vacuities usually present; ribs normal, lacking plate-like expansions. Horizon: Upper Permian: Zone, Beaufort Series, of South Africa; Zone IV of Russia; Kawinga Formation of Tanzania. GenusPROCYNOSUCHUS Broom 1937. Synonyms: ? Cyrbasiodon Broom 1931; Paracynosuchus Broom 1940a; Mygalesaurus Broom 1942; Aelurodraco Broom and Robinson 1948b; Leavachia Broom 1948; Galeophrys Broom 1948; Galecranium Broom 1948; Silphedestes Broom 1949; Protocynodon Broom 1949; Silphedocynodon Brink 1951; Scalopocynodon Brink 1961. DELAHARPEAE Broom 1937. Synonyms: ? Cyrbasiodon boycei Broom 1931; Procynosuchus rubidgei Broom 1938; Paracynosuchus rubidgei Broom 1940a; Nanictosuchus melinodon Broom 1940a; Nanicto­ saurus robustus Broom 1940b; Mygalesaurus platyceps Broom 1942; Aelurodraco microps Broom and Robinson 1948b; Leavachia duvenhagei Broom 1948; Galeophrys kitchingi Broom 1948; Galecranium liorhynchus Broom 1948; Silphedestes polyodon Broom 1949; Protocynodon pricei Broom 1949; Silphedocynodon gymnotemporalis Brink 1951; Leavachia microps Brink and Kitching 1951a; Leavachia gracilis Brink and Kitching 1951a; Scalopo­ cynodon gracilis Brink 1961. Horizon: Upper Permian: Daptocephalus Zone of South Africa. Remarks: Many genera and species have been based on juvenile specimens of Procynosuchus, including all forms placed in the Family Silphedestidae by Haughton and Brink (1954). Cyrbasiodon boycei is probably synonymous with P. 73

delaharpeae, but in view of the poor quality of the type specimen of the former species, we have chosen to retain the latter well-established name. (See paper by Mendrez in this volume, p. 51). D VINIA Amalitzky 1922. Synonyms: Permocynodon Woodward 1932. D VINIA PRIMA Amalitzky 1922. Synonyms: Permocynodon sushkini Woodward 1932. Horizon: Upper Permian: Upper Tatarian deposits of Arkhangel'sk region, Russia. Genus PARATHRINAXODON Parrington 1936. PARATHRINAXODON PROOPS Parrington 1936. Horizon: Upper Permian: Kawinga Formation of the Ruhuhu Valley, Tanzania. PROCYNOSUCHIDAE : Genus NANOCYNODON Tatarinov 1968b. NANOCYNODON SEDUCTUS Tatarinov 1968b. Horizon: Upper Permian: Upper Tatarian of Russia. Remarks: Tatarinov placed this species in the Galesauridae, but it is more likely a juvenile procynosuchid. FAMILY GALESAURIDAE Lydekker 1890. Includes: Nythosauridae Watson 1917; Cynosuchidae Haughton 1924a; Cynosauridae Haughton and Brink 1954; Thrinaxodontidae Watson and Romer 1956. Moderately advanced cynodonts with four upper and three lower incisors, no "precanine" maxillary teeth, and posterior postcanines with internal cingulum moderately developed or absent; dentary with well-developed coronoid process, incipiently-developed angular region, and masseteric fossa extending to lower border of the bone; postdentary elements slightly reduced in height from procynosuchid condition; palatal plates of the maxillae and palatines mayor may not meet at the midline; interpterygoidal vacuities present only in juveniles; thoracic and lumbar ribs with plate-like expansions. Horizon: Upper Permian to Lower Triassic: Beaufort Series (Upper Daptocephalus Zone to Cynognathus Zone, most abundant in Zone) of South Africa; of . Genus CYNOSAURUS Schmidt 1927. Synonyms: Cynosuchus Owen 1876; Cynosuchoides Broom 1931; Nanictosaurus Broom 1936; Mygalesuchus Broom 1942; Baurocynodon Brink 1951. CYNOSAURUS SUPPOSTUS (Owen 1876). Synonyms: Cynosuchus suppostus Owen 1876; Cynosuchus whaitsi Haughton 1918; Cynosaurus suppostus, Schmidt 1927; Cynosuchoides whaitsi Broom 1931; Nanictosaurus kitchingi Broom 1936; Mygalesuchus peggyae Broom 1942; Baurocynodon gracilis Brink 1951. Horizon: Upper Permian: Upper Daptocephalus Zone of South Africa. Remarks: This is the only undoubted galesaurid from the Permian. The last three synonyms are based on small juvenile specimens. Genus Owen 1859. Synonyms: Glochinodon van Hoepen 1916; Glochinodontoides Haughton 1924b. GALESAURUS PLANICEPS Owen 1859. Synonyms: Glochinodon detinens van Hoepen 1916; Glochino­ dontoides gracilis Haughton 1924b; Notictosaurus gracilis Broom and Robinson 1948a; Notictosaurus trigono­ cephalus Brink and Kitching 1951b. Horizon: Lower Triassic: Lystrosaurus Zone of South Africa. Remarks: Small, immature specimens have usually been 74

referred to the genus Galesaurus, large, mature specimens to Glochinodontoides. Genus Seeley 1894a. Synonyms: ? Nythosaurus Owen 1876; Ictidopsis Broom 1912a; No tic tosaurus Broom 1936; Micric todon Broom 1937. THRINAXODON LIORHINUS Seeley 1894a. Synonyms: ? Nythosaurus larvatus Owen 1876, Ictidopsis elegans Broom 1912a; Ictidopsis formosa van Hoepen 1916; Thrinaxodon putterilli Broom 1932; Notictosaurus luckhoffi Broom 1936; Micrictodon marionae Broom 1937. Horizon: Lower Triassic: Lystrosaurus Zone of South Africa; Fremouw Formation of Antarctica. Remarks: Nythosaurus larvatus Owen is based on the natural mould of a bearing impressions of the postcanine teeth. It is probably synonymous with either Thrinaxodon liorhinus or Platycraniellus elegans. We consider it to be indeterminate at present, and retain Seeley's name for this best-known species of cynodont. Genus PLATYCRANIELLUS van Hoepen 1917. Synonyms: Platycranion van Hoepen 1916; Platycranium van Hoepen 1917. PLATYCRANIELLUS ELEGANS (van Hoepen 1916). Synonyms: Platycranion elegans van Hoepen 1916; Platy- craniellus elegans van Hoepen 1917. Horizon: Lower Triassic: Lystrosaurus Zone of South Africa. Remarks: This species is known with certainty from the type only which comes from Harrismith, Orange Free State. A second specimen referred to this species by Brink (1954) is a Galesaurus. Genus TRIBOLODON Seeley 1894a. TRIBOLODON FRERENSIS Seeley 1894a. Horizon: Lower Triassic: Cynognathus Zone of South Africa. Remarks: This is the youngest species referable with certainty to the Galesauridae. Though frequently classified as a cynognathid, it is a typical galesaurid in its known features.

FAMILY CYNOGNATHIDAE Watson 1917. Includes: Karromysidae Haughton 1924a. Advanced carnivorous cynodonts of large size, with elongated facial region and short temporal region; , , and occipital plate of the squamosal very broad and heavy; occipital portion of the squamosal not emarginated dorsally (as in other advanced cynodonts); dentary very large, with broad posterodorsally-directed coronoid process and distinct angle; postdentary elements greatly reduced in dorsoventral dimension to form a sturdy rod; surangular forms accessory articulation with the squamosal; posterior laterally compressed, with three to six{?) cusps aligned antero­ posteriorly, and lacking cingulum cusps except in very young individuals; lumbar ribs with overlapping expansions. Horizon: Lower Triassic: Cynognathus Zone of South Africa and Lesotho (reference to Molteno Beds of Lesotho is incorrect. Turner: in press); Puesto Viejo Formation of Argentina. Genus CYNOGNATHUS Seeley 1895b. Synonyms: Karoomys Broom 1903b; Lycognathus Broom 1913b; Lycochampsa Broom 1915b; Cynidiognathus Haughton 1922; Lycaenognathus Broom 1925; Cynogomphius Broom 1932; Cistecynodon Brink and Kitching 1953. CYNOGNATHUS CRATERONOTUS Seeley 1895b. Synonyms: . Cynognathus berryi Seeley 1895b; Cynognathus platyceps Seeley 1895b; Karoomys browni Broom 1903b; Nythosaurus browni Broom 1912a; Lycognathus ferox 75

Broom 1913b; Lycochampsa ferox Broom 1915b; Cynidiognathus longiceps Haughton 1922; Cynidiognathus broomi Haughton 1922; Lycaenognathus platyceps Broom 1925; Lycaenognathus kannemeyeri Broom 1931; Cynogomphius berryi Broom 1932; Cynidiognathus merenskyi Broili and Schroder 1935b; Cistecynodon parvus Brink and Kitching 1953; Cynognathus minor Bonaparte 1967a. Horizon: Same as for family. Remarks: Generic and specific distinctions within the Cynognathidae have been based on characters which vary with age ( number and , skull propor­ tions) and are influenced by postmortem deformation. It seems best to us to recognize but a single species, pending a thorough revision of the family. Karoomys, Cistecyno­ don, and Nythosaurus browni are based on tiny juveniles of Cynognathus. FAMILY CHINIQUODONTIDAE von Huene 1936. Advanced carnivorous cynodonts of small to large size, in which secondary palate extends nearly to or beyond the posterior end of the tooth row (in contradistinction to all other families-except the - in which the secondary palate ends well in front of the last tooth) ; occipital portion of the squamosal emarginated dorsally; dentary very large, contacting the squamosal in at least one species; postdentary elements reduced to a narrow rod; surangular contacts the squamosal; postcanines vary greatly in morphology, in some species are sectorial with small or no cingulum cusps, in others have broad lingual shelves which contact similar shelves in the occluding ; this family probably contains the immediate ancestors of . Horizon: Middle and Upper Triassic: Middle Triassic Chaiiares F orma­ tion of Argentina, of Tanzania; Middle or Upper Triassic of Brazil; Upper Triassic Ischi­ gualasto Formation of Argentina. Genus von Huene 1936. CHINIQUODON THEOTONICUS von Huene 1936. Horizon: Middle and Upper Triassic: Middle Triassic Chaiiares Formation of Argentina; Middle or Upper Triassic Santa Maria Formation of Brazil; Upper Triassic of Argentina. Remarks: This species is poorly understood; possibly some of the specimens referred to it from the Chaiiares and Ischigualasto formations do not belong here. Genus BELESODON von Huene 1936. BELESODON MAGNIFICUS von Huene 1936. Horizon: Middle or Upper Triassic: Santa Maria Formation of Brazil. Remarks: Belesodon is not clearly separable from Chiniquodon except on the basis of features which may merely reflect ontogenetic differences. However, because important features of the postcanine dentition are not known for either genus, we prefer to maintain them as distinct for the present. Genus ALEODON Crompton 1955. ALEODON BRACHYRAMPHUS Crompton 1955. Horizon: Middle Triassic: Manda Formation of Tanzania. Remarks: Undescribed specimens being studied by Crompton indicate that this species is a chiniquodontid, the only one known from Africa. Genus PROBELESODON Romer 1969. PROBELESODON LEWISI Romer 1969. Horizon: Middle Triassic: Chaiiares Formation of Argentina. 76

GenusPROBAINOGNATHUS Romer 1970. JENSENI Romer 1970. Horizon: Middle Triassic: Chaiiares Formation of Argentina. Remarks: This species possesses a contact between dentary and squamosal bones, generally consider-ed one of the principal diagnostic characters of mammals. Despite previous remarks to the contrary (Barghusen and Hopson, 1970), Probainognathus is probably very close to the line which gave rise to the Class Mammalia.

FAMILY TRITHELEDONTIDAE Broom 1912b. Includes: Ictidosauridae Young 1947; Diarthrognathidae Crompton 1958. Very advanced carnivorous cynodonts of small size in which incisors number two above and below; in some species the upper postcanines (and probably the lowers as well) have a transversely-oriented cutting edge, in others the uppers have an oblique and the lowers a longitudinal cutting edge; secondary palate very long (as in the Chiniquodontidae); postorbital bar absent; dentary contacts the squamosal at least in some. Horizon: Upper Triassic: Stormberg Series (Red Beds and Cave Sandstone) of South Africa and Lesotho; Los Colorados Formation of Argentina (Bonaparte, personal communication). Genus TRITHELEDON Broom 1912b. TRITHELEDON RICONOI Broom 1912b. Horizon: Upper Triassic: Red Beds of South Africa. Remarks: Crompton (in Hopson and Crompton, 1969) has restudied the type and only specimen and has determined its close affinities with and "Diarthrog­ nathus". For this reason, we use the family name Tritheledontidae Broom 1912 for all of the forms called "ictidosaurs" . Genus PACHYGENELUS Watson 1913. Synonyms: Diarthrognathus Crompton 1958. PACHYGENELUS MONUS Watson 1913. Synonyms: Diarthrognathus broomi Crompton 1958. Horizon: Upper Triassic: Red Beds and Cave Sandstone of South Africa and Lesotho. Remarks: Diarthrognathus broomi is based on two juvenile specimens which are probably, though not certainly, referable to P. monus. Although a specific distinction may prove to be valid, it is doubtful that generic differences exist. SUPERFAMILY TRITYLODONTOIDEA Simpson 1928 (New rank, erected as suborder). Cynodonts of omnivorous or herbivorous habits in which some or all of the postcanine teeth have transversely-widened crowns which meet in complex ; dentary very large with large coronoid process and distinct angular region often with a true angular process; postdentary elements reduced to narrow rod; surangular contacts squamosal; occipital portion of the squamosal emarginated dorsally; lumbar ribs primitively with overlapping expansions, but rib specializations lost in later forms.

FAMILY Haughton 1924a. Includes: Gomphognathidae Broom 1903a; von Huene 1936; Gomphodontosuchidae Watson and Romer 1956; Trira­ chodontidae Romer 1967. Primitive to advanced cynodonts of omnivorous to herbivorous habits in which canines are not lost, postcanine teeth are single-rooted and upper postcanines are much wider than long; postorbital bar and prefrontal and postorbital bones present; lumbar ribs with overlapping expansions except in very advanced forms. Horizon: Lower to Upper Triassic: Lower Triassic Cynognathus Zone of South Africa, Puesto Viejo Formation of Argentina; Lower or Middle Triassic "Sinokannemeyeria Fauna Beds" of Shansi, China; 77

Middle Triassic Las Cabras and Chaiiares formations of Argentina, Ntawere Formation of Zambia, and Manda Formation of Tanzania; Middle or Upper Triassic Santa Maria Formation of Brazil, and Potrerillos Formation of Argentina; Upper Triassic Ischigualasto Formation of Argentina, and Newark Group of Nova Scotia, Canada.

SUBFAMILY DIADEMODONTINAE New Rank. Includes: Eudiademodontinae Lehman 1961; Gomphodontoinae Lehman 1961. Primitive omnivorous or herbivorous diademodontids in which the postcanine dentition consists of an anterior series of simple pointed teeth, a middle series of transversely-expanded "molariform" teeth, and a posterior series grading from "sub-molariform" to sectorial; upper "molariform" teeth wider than long with a large outer cusp and one or two smaller inner cusps connected by a centrally-located transverse ridge; lower "molariform" teeth nearly circular in crown view with large outer and inner cusps .ioined by a centrally-located transverse ridge; lumbar ribs with broad overlapping expansions. Genus DIADEMODON Seeley 1894b. Synonyms: ? Cynochampsa Owen 1859; Gomphognathus Seeley 1895a; Octagomphus Broom 1919; Cyclogomphodon Broom 1919; Protacmon Watson 1920; Sysphinctostoma Broili and Schroder 1936; Gomphodontoides Brink and Kitching 1951b; Cragievarus Brink 1965. DIADEMODON TETRA GONUS Seeley 1894b. Synonyms: ? Cynochampsa laniaria Owen 1859; Diademodon mastacus Seeley 1894b; Diademodon browni Seeley 1894b; Gomphognathus kannemeyeri Seeley 1895a; Gomphognathus polyphagus Seeley 1895a; Diademodon entomophonus Seeley 1908; Gomphognathus minor Broom 1911; Diademodon platyrhinus Broom 1913a; Trirachodon browni Broom 1915a; Cyclogomphodon platyrhinus Broom 1919; Octagomphus woodi Broom 1919; Protacmon brachyrhinus Watson 1920; Gomphog­ nathus grossarthi Broili and Schroder 1935a; Gomphog­ nathus broomi Broili and Schroder 1935a; Sysphincto­ stoma smithi Broili and Schroder 1936; Protacmon reubsameni Broom 1950; Sysphinctostoma gracilis Broom 1950; Gomphodontoides megalops Brink and Kitching 1951b; Diademodon parringtoni Brink 1955; Diademodon laticeps Brink 1955; Diademodon rhodesiensis Brink 1963; Cragievarus kitchingi Brink 1965. Horizon: Lower Triassic to Middle Triassic: Lower Triassic Cynognathus Zone of South Africa; Middle Triassic Ntawere Formation of Zambia. Remarks: The named species of African diademodontines have been based on dental differences and variations in skull sizes and proportions which can be attributed to onto­ genetic variation and, perhaps, , as well as to postmortem distortion. In the absence of valid criteria for distinguishing species of Diademodon; we prefer to recognize a single species. The earliest named diademodontine, Cynochampsa laniaria, is based on a fragmentary snout lacking postcanine teeth; we prefer to consider it a nomen vanum.

DIADEMODONTINAE incertae sedis: Genus ORDOSIODON Young 1961. ORDOSIODON LINCHEYUENSIS Young 1961. Horizon: Lower or Middle Triassic: Beds approximately equivalent to Cynognathus Zone of Shansi, China. 78

Remarks: This species is based on a small dentary probably of juvenile diademodontine.

SUBFAMILY TRIRACHODONTINAE New Rank. Primitive omnivorous or herbivorous diademodontids In which the postcanine dentition consists of transversely-expanded "molariform" teeth, plus one or two sectorial teeth at the posterior end of the tooth row (simple anterior teeth and "sub-molariform" posterior teeth are lacking); upper and lower "molariforms" of similar morphology, crowns with three main cusps in a transverse row across the centre of the tooth with cusps connected by ridges, margins of the crowns with continuous rim o~ small cingulum cusps; lumbar ribs with broad overlapping expansIOns. Genus TRIRACHODON Seeley 1894b. Synonyms:Trirachodontoides Broom 1932; Inusitatodon Brink and Kitching 1953. TRIRACHODON BERRYI Seeley 1894b. Synonyms: Trirachodon kannemeyeri Seeley 1895a; Trira­ chodon minor Broom 1905; Trirachodontoides berryi Broom 1932; Inusitatodon smithi Brink and Kitching 1953. Horizon: Lower Triassic: Cynognathus Zone of South Africa. Remarks: The named species are based on dental and size characteristics which change on togeneticall y. Genus CRICODON Crompton 1955. CRICODON METABOLUS Crompton 1955. Horizon: Middle Triassic: Manda Formation of Tanzania.

TRIRACHODONTINAE incertae sedis: Genus SINOGNATHUS Young 1959. SINOGNATHUS GRACILIS Young 1959. Horizon: Lower or Middle Triassic: "Sinokannemeyeria Fauna Beds" of Shansi, China. Remarks: Young believed this form to be a galesaurid, but it is clearly more advanced and appears to have "molariform" postcanine teeth of diademodontid, especially triracho­ dontine, appearance.

SUBFAMILY TRAVERSODONTINAE Lehman 1961. Includes: Gom phodon tosuchinae Lehman 1961. Advanced herbivorous diademodontids in which the postcanine denti­ tion consists of transversely-expanded "molariform" teeth, with one or two sectorial teeth occurring only in certain ontogenetic stages of the more primitive species; upper postcanines with three main cusps in a transverse row behind the centre of the crown, with the outer cusp being the largest and possessing a vertical shear surface on its inner face, and with a small to very large basin in the central portion of the crown; lower· postcanines with two main cusps oriented more or less transversely on the anterior half of the crown and a basined "heel" on the posterior half of the crown, with the outer cusp possessing a vertical shear surface on its outer face; lower canine reduced in advanced forms; lumbar ribs with broad overlapping expansions in early members, but these become progressively reduced and ultimately lost in advanced members of the group.

Genus TRA VERSODON von Huene 1936. TRA VERSODON STAHLECKERI von Huene 1936. Synonyms: ? major von Huene 1936. Horizon: Middle or Upper Triassic: Santa Maria Formation of Brazil. Remarks: ? Traversodon major is based on fragments which differ from T. stahleckeri only in size. ------

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Genus GOMPHODONTOSUCHUS von Huene 1928. GOMPHODONTOSUCHUS BRASILIENSIS von Huene 1928. Horizon: Middle or Upper Triassic: Santa Maria Formation of Brazil. Genus PASCUALGNATHUS Bonaparte 1966. PASCUALGNATHUS POLANSKII Bonaparte 1966. Horizon: Lower Triassic: Puesto Viejo Formation of Argentina. Remarks: The earliest and most primitive traversodontine, it shows many resemblances to Diademodon indicating a diademodontine origin of traversodontines. Genus ANDESCYNODON Bonaparte 1967b. ANDESCYNODON MENDOZENSIS Bonaparte 1967b. Horizon: Middle Triassic: Las Cabras Formation of Argentina. Remarks: A primitive traversodontine, slightly more advanced than Pascualgnathus. Genus SCALENODON Crompton 1955. SCALENODON ANGUSTIFRONS (Parrington 1946). Synonyms: Trirachodon angusttfrons Parrington 1946; Scalenodon angusttfrons Crompton 1955. Horizon: Middle Triassic: Manda Formation of Tanzania. Genus Brink 1963. LUANGWA DR YSDALLI Brink 1963. Horizon: Middle Triassic: Ntawere Formation of Zambia. Remarks: Although its postcanine morphology is not ade- quately known, this species seems to be distinct. Genus Romer 1967. MASSETOGNATHUS PASCUALI Romer 1967. Synonyms: Massetognathus teruggii Romer 1967. Horizon: Middle Triassic: Chanares Formation of Argentina. Remarks: The type skull of M. teruggii differs from that of M. pascual£ in no significant features other than size. It is here considered to be an old individual of the latter species. Genus Cabrera 1943. Synonyms: Theropsis Cabrera 1943 ; Proexaeretodon Bonaparte 1963b. EXAERETODON ARGENTINUS (Cabrera 1943). Synonyms: B elesodon? argentinus Cabrera 1943; Exaeretodon frenguellii Cabrera 1943; Theropsis robusta Cabrera 1943; Exaeretodon argentz"nus Bonaparte 1962; Proexaeretodon vincei Bonaparte 1963b. Horizon: Upper Triassic: Ischigualasto Formation of Argentina. Remarks: With the exception of the following form, all Ischigualasto traversodon tines can be accommodated in a ~ingle species for which the name E. argentinus has page priority. Genus ISCHIGNATHUS Bonaparte 1963a. ISCHIGNATHUS SUDAMERICANUS Bonaparte 1963a. Horizon: Upper Triassic: Ischigualasto Formation of Argentina. Remarks: This species is similar to, but apparently distinct from, Exaeretodon. Genus SCALENODONTOIDES Crompton and Ellenberger 1957. SCALENODONTOIDES MACRODONTES Crompton and Ellenberger 1957. Horizon: Upper Triassic: Lower part of the Red Beds, Stormberg Series, of Lesotho. Remarks: The type specimen was said to be from the Molteno Beds, but Crompton (in Cox 1969) and Turner (in press) have since determined that it is from the overlying Red Beds. Scalenodontoides is very similar to Exaeretodon and the two may prove to be identical. 80

TRA VERSODONTINAE incertae sedis: Genus THEROPSODON von Huene 1950. THEROPSODON NJALILUS von Huene 1950 nomen vanum. Horizon: Middle Triassic: Manda Formation of Tanzania. Remarks: This form is based on a complete but poorly preserved skull with lower in place. Because several other genera and species of traversodontines, mostly undescribed, are now known from the Manda Formation and are differentiated primarily on the basis of postcanine morphology, which is not readily available in the type specimen of T. njalilus, we believe it is best to consider it a nomen vanum. Genus COLBERTOSAURUS Minoprio 1957. Synonym: Colbertia Minoprio 1954. COLBERTOSAURUS MURALIS (Minoprio 1954). Synonyms: Colbertia muralis Minoprio 1954; Colbertosaurus m uralis Minoprio 1957. Horizon: Middle or Upper Triassic: Potrerillos Formation of Argentina. Remarks: This species is inadequately known, being based on a fragmentary dentary. Bonaparte (1966) compares it to the traversodon tines A ndescynodon and Pascualgnath us. FAMILY TRITYLODONTIDAE Cope 1884. Includes: Bienotheriidae Young 1940. Very advanced herbivorous cynodonts in which one pair of upper and lower incisors is greatly enlarged, canines are absent, and multiple­ rooted postcanine teeth three (upper) or two (lower) longitudinal rows of crescentic cusps; postorbital bar and prefrontal and postorbital bones absent; lumbar ribs lack overlapping expansions. Horizon: Upper Triassic to Middle : Upper Triassic Red Beds and Cave Sandstone, Stormberg Series, of South Africa and Lesotho; Lufeng Series of Yunnan, China; Los Colorados Forma­ tion of Argentina; of the United States; Rhaetic of Germany; Lower Jurassic fissures of England; Stonesfield Slate of England. Genus TRITYLODON Owen 1884. Synonyms: LikhoeliaGinsbu!g 1961; Tritylodontoideus F ourie 1962. TRITYLODON LONGAEVUS Owen 1884. Synonyms: Likhoelia ellenbergeri Ginsburg 1961; ? Tritylodon­ toideus maximus Fourie 1962; ? Tritylodontoides maxi­ Fourie 1963; Horizon: Upper Triassic: Red Beds and Cave Sandstone, Stormberg Series, of South Africa and Lesotho. Remarks: The generic name Tritylodon should be restricted to southern African forms and should not be applied to isolated teeth from the Rhaeto-Lias of Europe (see Tritylodon fraasi below), as the latter are, in fact, generically indeterminate. Likhoelia is based on a juvenile specimen of T. longaevus. Kitching (ms.) believes Trityl­ odontoideus to be a large T. longaevus.

Genus BIENOTHERIUM Young 1940. BIENOTHERIUM YUNNANENSE Young 1940. Synonyms: Bienotherium elegans Young 1940. Horizon: Upper Triassic: Lower Lufeng Series of. Yunnan, China. Remarks: B. elegans is based on an immature B. yunnanense. BIENOTHERIUM MAGNUM Chow 1962. Horizon: Upper Triassic: Lower Lufeng Series of Yunnan, China. Remarks: B. magnum is recognized as a distinct species because 81

it comes from a higher horizon than B. yunnanense and is much larger. - Genus LUFENGIA Chow and Hu 1959. LUFENGIA MINOR (Young 1947). Synonyms: Bienotherium minor Young 1947; Lufengia deli­ cata Chow and Hu 1959; Lufengia minor new combina­ tion. Horizon: Upper Triassic: Lower Lufeng Series of Yunnan, China. Remarks: Hopson (ms.) believes B. minor Young pertains to the genus Lufengia. Genus Hennig 1922. Synonyms: Mucrotherium E. von Heune 1933 Uniserium E. von Huene 1933. OLIGOKYPHUS TRISERIALIS Hennig 1922. Synonyms: Oligokyphus biserialis Hennig 1922; Mucrotherium cingulatum E. von Ruene 1933; Uniserium enigmaticum E. von Huene 1933. Horizon: Lower Jurassic: Liassic Bonebed of Germany. OLIGOKYPHUS MAJOR Kuhne 1956. Synonyms: Oligokyphus minor Kuhne 1956. Horizon: Lower Jurassic: Lower Lias Fissures of Somerset, England. Remarks: Kuhne described two size groups of Oligokyphus from a single fissure to which he gave separate names. We believe it more likely that the groups represent male and of a single species for which the name O. major has priority. Genus STEREOGNATHUS Charlesworth 1855. STEREOGNATHUS OOLITICUS Charlesworth 1855. Horizon: Middle Jurassic: Stonesfield slate of Oxfordshire, England. Remarks: This is the latest known therapsid . TRITYLODONTIDAE OF UNCERTAIN TAXONOMIC POSITION TRITYLODON FRAASI Lydekker 1887 nomen vanum Synonyms: 'Triglyphus" O.Fraas 1866; Tritylodon fraasi Lydekker 1887; Triglyphus fraasi Hennig 1922. Horizon: Rhaeto-Liassic Bonebed of Wurttemberg, Germany. Remarks: The type and only specimen of this species, an isolated upper postcanine tooth, is lost. Because its crown pattern is identical to that of several genera of tritylodon­ tids, it is not diagnostic and is best regarded as a nomen vanum. CHALEPOTHERIUM PLIENINGERI (Ameghino 1903) nomen vanum. Synonyms: Microlestes plieningeri Ameghino 1903; Chale­ potherium plieningeri Simpson 1928. Horizon: Rhaeto-Liassic Bonebed of Wurttemberg, Germany. Remarks: The type and only specimen of this species consists of a damaged upper postcanine tooth which is not diagnostic as to genus or species; therefore, C. plieningeri is a nomen vanum. CYNODONTIA incertae sedis: Genus MICROHELODON Broom 1931. MICROHELODON EUMERUS (Seeley 1895a) nomen vanum. Synonyms: Microgomphodon eumerus Seeley 1895a; Micro- helodon eumerus Broom 1931. Horizon: Lower Triassic: Cynognathus Zone of South Africa. Remarks: The type and only specimen is a damaged snout which may pertain to a bauriamorph or to a cynodont. Seeley associated a cynodont skeleton with the type, but 82

Broom (1931) and Brink (1955) consider this association to be incorrect. GenusARCHAEODONvon Huene 1925. ARCHAEODON REUNINGI von Huene 1925. Horizon: Upper Triassic? : "Youngest Stormberg" equivalent? of South-West Africa. Remarks: The type and only specimen is an isolated tooth with divided , but lacking the crown. It does not appear to be referable to the Tritylodontidae and is unlike any known Triassic mammal. We question the correctness of the reported Triassic age. Genus DROMATHERIUM Emmons 1857. DROMATHERIUM SYL VESTRE Emmons 1857. Horizon: Upper Triassic: Cumnock Formation, Newark Group, of North Carolina, United States. Remarks: This incomplete dentary with damaged postcanine teeth may belong to a cynodont or to a mammal. Its affinities are at present indeterminate. Genus MICROCONODON Osborn 1886. Synonyms: Tytthoconus Palmer 1903. MICROCONODON TENUIROSTRIS Osborn 1886. Synonyms: Tytthoconus tenuirostris Palmer 1903. Horizon: Upper Triassic: Cumnock Formation, Newark Group, of North Carolina, United States. Remarks: This tiny dentary is possibly a mammal, or it may be a cynodont, most likely a chiniquodontid, close to the reptile-mammal class boundary. Genus KUNMINIA Young 1947. KUNMINIA MINIMA Young 1947 nomen vanum. Horizon: Upper Triassic: Lower Lufeng Series of Yunnan, China. Remarks: This poorly-preserved little skull may be that of a mammal, possibly the same as oehleri from the same beds. The specimen as now known is indeter­ minate and the name is best considered a nomen vanum. Genus TRICUSPES E. von Huene 1933. TRICUSPES TUBINGENSIS E. von Huene 1933. Horizon: Lower Jurassic: Liassic Bonebed of Germany. Remarks: This isolated tooth may pertain to a cynodont, to a mammal, or to some unknown reptilian type. Genus EORAETIA Dietrich 1937. EORAETIA SIEGERTI Dietrich 1937. Horizon: Upper Triassic or Lower Jurassic: Rhaeto-Lias of Halberstadt, G~rmany. Remarks: The affinities of this isolated ulna are uncertain.

REFERENCES - --- , (1963a). Descripcion de Ischignathus AMALITZKY, V., (1922). Diagnoses of the new sudamericanus n. gen. et n. sp., nuevo cino· forms of and from the donte gonfodonte del Triasico Medio superior Upper Permian of North Dvina. Bull. Acad. de San Juan, Argentina. Acta geol. lilloana, 4, Sci. St. Petersburg, (6) 16, 329-340. 111-128. AMEGHINO, F., (1903). Los diprotodontes del ----, (1963b). Un nuevo cinodonte gonfodonte orderr de los plagiaulacoideos. An. Mus. naco del Triasico Medio superior de San Juan, Buenos Aires, (3) 2, 81-192. Proexaeretodon vincei. Ibid., 129-133. BARGHUSEN, H. R., and HOPSON, J. A., (1970). ----, (1966). Sobre nuevos terapsidos Triasicos Dentary-squamosal joint and the origin of hallados en el centro do la provincia de mammals. Science, N. Y., 168,573-575. Mendoza, Argentina. Ibid., 8, 91-100. BONAPARTE, J.-F., (1962). Descripcion del ----, (1967a). Cynognathus minor n. sp., craneo y mandibula de Exaeretodon frengu­ (Therapsida-Cynodontia), nueva evidencia de ellii, Cabrera. Pub. Mus. Cienc., Mar del Plata, vinculacion faunistica. Afro-Sudamericana a 1, 135-202. principios del Triasico. Strati- 83

graphy, LV.G.S. Symposium, Mar Del Plata, ----, (1915b). Catalogue of types and figured 273-28l. specimens of vertebrates in the American ----, (196 7b). Dos nuevas "faunas" de Museum of . 2. Permian, Triasicos de Argentina. Ibid., 283-306. Triassic, and Jurassic reptiles of South Africa. BRINK, A. S., (1951). Studies of Karroo reptiles: Bull. Am. Mus. nat. Hist., 25, 105-164. 1. Some small cynodonts. S. Afr. J. Sci., 47, ----, (1919). On the genus Comphognathus and 338-342. its allies. Rec. Albany Mus., 3, 223-232. ----, (1954). Note on a new Platycraniellus ----, (1925). On some carnivorous . skull. Navors. nas. Mus. Bloemfontein, 1, Ibid., 309-326. 127-129. ----, (1931). Notices of some new genera and ----, (1955). A study on the skeleton of species of Karroo fossil reptiles. Ibid., 4, Diademodon. Palaeont. afr., 3, 3-39. 161-166. ----, (1961). A new type of primitive cynodont. ----, (1932). The mammal-like reptiles of South Ibid., 7, 119-154. Africa and the origin of mammals. H. F. and ----, (1963). Two cynodonts from the Ntawere G. Witherby, London, 376 pp. Formation in the Luangwa Valley of Northern ----, (1936). On some new genera and species of Rhodesia. Ibid., 8, 77-96. Karroo fossil reptiles with notes on some ----, (1965). A new gomphodont cynodont others. Ann. Transv. Mus., 18, 349-386. from the Cynognathus Zone of South Africa. ----, (1937). A further contribution to our Ibid., 9, 97-105. knowledge of the fossil reptiles of the Karroo. ----, and KITCHING, J. W., (1951a). Studies of Proc. zool. Soc. Lond., (B) 107,299-318. Karroo reptiles: 2. On Leavachia, a procyno­ ----, (1938). The origin of the cynodonts, Ann. suchid cynodont from the Middle Cz"stece­ Transv. Mus., 19, 279-288. phalus Zone. S. Afr. J. Sci., 47 342-347. ----, (1940a). Some new Karroo reptiles from ----, (1951b). Some theriodonts in the collec­ the Graaff-Reinet District. Ibid., 20, 71-87. tion of the Bernard Price Institute. Ann. Mag. ----, (1940b). On some new genera and species nat. Hist., 4(12), 1218-1236. of fossil reptiles from the Karroo beds of ----, (1953). On some new Cynognathus Zone Graaff-Reinet. Ibid., 157-192. specimens. Palaeont. .cdr., 1, 29-48. .. ----, (1942). Evidence of a new sub- of BROIL!, F., and SCHRODER, J., (1935a). Vber mammal-like reptiles. Bull. S. Afr. Mus. Ass., den Schadel von Comphognathus Seeley. Sber. 2,386. bayer. Akad. Wiss. Math.-naturw. Abt., 1935, ----, (1948). A contribution to our knowledge 115-182. of the vertebrates of the Karroo beds of South ----, (1935b). Uber den Schadel von Cynidiog­ Africa. Trans. R. Soc. Edinb., 61,577-629. nathus Haughton. Ibid., 199-222. ----, (1949). New fossil reptile genera from the ----, (1936). Ein neuer Galesauride aus der Bernard Price collection. Ann. Transv. Mus., Cynognathus-Zone. Ibid., 1936, 269-282. 21, 187-194. BROOM, R., (1903a). On the classification of the ----, (1950). Some fossil reptiles from the theriodonts and their allies. Rep. S. Afr. Ass. Karroo beds of Lady' Frere. S. Afr. J. Sci., 47, Advmt. Sci., 1903,286- 294. 86-88. ----, (1903b). On the lower jaw of a small ----, and ROBINSON, J. T., (1948a). Some new mammal from the Karroo beds of Aliwal fossil reptiles from the Karroo beds of South North, South Africa. Ceol. Mag. , (4) 10, 345. Africa. Proc. !. Soc. Lond., 118, 392-407. ----, (1905). Preliminary notice of some new ----, (1948b). On some new types of small fossil reptiles collected by Mr. Alfred Brown at carnivorous mammal-like reptiles. R. Soc. S. Aliwal North, South Africa. Rec. Albany Mus., Afr. Spec. Pub I. , Robert Broorn Comm. Vol., 1,269-275. 29-44. ----, (1911). On the structure of the skull in CABRERA, A., (1943). El primer hallazgo de cynodont reptiles. Proc. zoo!. Soc. Lond., terapsidos en La Argentina. Notas. Mus. La 1911, 893-925. Plata, 8, 317 -33l. ----. (1912a). On some new fossil reptiles from CHARLESWORTH, E., (1855). (No title). Rep. the Permian and Triassic of South Africa. Brit. Ass. Advmt. Sci., 1854, Abstracts, p. 80. Ibid., 1912,859-876. ----, (1912b). On a new type of cynodont from CHOW, M. M., (1962). A tritylqdontid specimen from Lufeng, Yunnan. Vertebr. palasiat., 6, the Stormberg. Ann. S. Afr. Mus., 7, 334-336. ----, (1913a). On evidence of a mammal-like 365-367. ----, and HU, C. C., (1959). A new trityl­ dental succession in the cynodont reptiles. odontid from Lufeng, Yunnan. Ibid., 3, 9-12. Bull Am. Mus. nat. Hist., 32, 465-468. ----, (1913b). On some new carnivorous therap­ COPE, E. D., (1884). The Tertiary Marsupialia. sids. Ibid., 557-56l. Am. Nat., 18, 686-697. ----, (1915a). On some new carnivorous Therap­ COX, C. B., (1969). Two new from sids in the collection of the British Museum. the Triassic Ntawere Formation, Zambia. Bull. Proc. zool. Soc. Lond., 1915, 163-173. Br. Mus. nat. Hist. Ceo!., 17, 257-294.

G 84

CROMPTON, A. W., (1955). On some Triassic amerikanischen Condwanalandes. Lieferung 2, cynodonts from Tanganyika. Proc. zool. Soc. Franz F. Heine, Tiibingen, p. 93-159. Re­ Lond., 125, 617-669. printed in Huene, 1944, C. H. Beck, Munich, ----, (1958). The cranial morphology of a new 1935-1942,332 p. genus and species of ictidosaurian. Ibid., 130, --- -, (1950). Die Theriodontier des ostafrika­ 183-216. nischen Ruhuhu-Gebietes in der Tiibinger ----, and ELLENBERGER, F., (1957). On a Sammlung. Neues. Jb. Ceo!. Paliiont., Abh., new cynodont from the Molteno Beds and the 92,47-136. origin of the tritylodontids. Ann. S. Afr. Mus., KUHNE, W. G., (1956). The Liassic therapsid 44, 1-14. Oligokyphus. British Museum (Natural His­ DIETRICH, W.O., (1937). tiber eine Saugetierelle tory), London, 149 p. aus dem von Halberstadt. Neues Jb. Miner. LEHMAN, J.-P., (1961). Cynodontia. p. 140-19l. Ceol. Paliiont., Beilage-Band, 77,310-319. In Traite de Paleontologie, J. Piveteau, Ed., EMMONS, E., (1857). American geology, Pt. 6, Tome 6, Vol. 1, 1 138 p. New York, 152 p. LYDEKKER, R., (1887). Catalogue of the fossil FOURIE, S., (1962). Notes on a new tritylodontid Mammalia in the British Museum, Pt. 5. from the Cave Sandstone of South Africa. London, 345 p. Navors. nas. Mus. Bloemfontein, 2, 7-19. ----, (1890). Catalogue of the fossil Reptilia and ----, (1963). A new tritylodontid from the Cave Amphibia in the British Museum, Pt. 4. Sandstone of South Africa. , Lond., London, 295 p. , 198,20l. MINOPRIO, J. L., (1954). Theriodonte en el FRAAS, O. F. von, (1866). Vor der Siindflut. Triasico de Mendoza. An. Soc. cient. argent., Stuttgart, 512 p. 157,31-37. GINSBURG, L., (1961). Un nouveau tritylodonte ----, (1957). Nota aclaratoria sobre Colbertia du Trias superieur du Basutoland (Afrique du muralis (Cambio de denominaci6n). Ameghini­ Sud). C. r. Acad. Sci. Paris, 252, 3 853-3 854. ana, 1, 114. HAUGHTON, S. H., (1918). Some new carni­ OSBORN, H. F., (1886). A new mammal from the vorous Therapsida, with notes upon the American Triassic. Science, N.Y., 8, 540. brain-case in certain species. Ann. S. Afr. Mus., 12, 175-216. OWEN, R., (1859). On some reptilian from ----, (1922). On some Upper Beaufort Therap­ South Africa. Q. J!. geo!. Soc. Lond., 1860, sida. Trans. R. Soc. S. Afr., 10,299-307. 16, 49-63. ----, (1924a). A bibliographic list of Pre­ ----, (1876). Descriptive and illustrated cata­ Stormberg Karroo Reptilia, with a table of logue of the fossil Reptilia of South Africa in horizons. Ibid., 12, 51-104. the collection of the British Museum. London, ----, (1924b). On Cynodontia from the Middle 88 p. Beaufort beds of Harrismith, Orange Free ----, (1884). On the skull and dentition of a State. Ann. Transv. Mus., 11, 74-92. Triassic mammal (Tritylodon longaevus) from ----, and BRINK, A. S., (1954). A biblio­ South Africa. Q. J!. geo!. Soc., Lond. 40, graphical list of Reptilia from the Karroo Beds 146-152. of Africa. Palaeont. afr., 2,1-187. PALMER, T. S., (1903). Some new generic names HENNIG, E., (1922). Die Saugerzahne des wiirt­ of mammals. Science, N. Y. 17,873. tembergischen Rhat-Lias-Bonebeds. Neues. Jb. PARRINGTON, F. R., (1936). On the tooth Miner. Ceo!. Paliiont., Bei!. Bd., 46, 181-267. replflcement in theriodont reptiles. Phil. Trans. HOEPEN, E. C. N. van, (1916). Preliminary notice R. Soc. (B) 226 121-142. of new reptiles of the Karroo Formation. Ann. ----, (1946). On the cranial anatomy of Transv. Mus., 5, no. 3, suppl. 2, 2 p. cynodonts. Proc. zoo!. Soc. Lond., 116, - ---, (1917). Note on Myriodon and Platy­ 181-197. cranium. Ibid., 5,217. ROMER, A. S., (1966). Vertebrate , HOPSON, J. A., and CROMPTON, A. W., (1969). 3rd. Ed., Univ. of Chicago Press, Chicago, 468 Origin of mammals. p. 15-72, In Evolutionary p. Biology 3, T. Dobzhansky et al., Eds., ----, (1967). The Chaiiares (Argentina) Triassic Appleton-Century-Crofts, New York. reptile fauna: 3. Two new gomphodonts, HUENE, E. von, (1933). Zur Kenntnis des wiirt­ Massetognathus pascuali and M. teruggii. Brevi­ tembergischen Ratbonebeds mit Zahnfunden ora, 264, 1-25. neuer Sauger und saugeranlicher Reptilien Jb. ----, (1969). The Chaiiares (Argentina) Triassic Ver. vater!. Naturk. Wiirtt., 89, 65-128. reptile fauna: 5. A new chiniquodontid cyn­ HUENE, F. von, (1925). Triassicher Saugetierzahn odont; Probelesodon lewisi-cynodont ances­ aus Siidwestafrika. Zenth!. Miner. Ceol. try. Ibid., 333, 1-24. Paliiont, 1925, 174-18l. ----, (1970). The Chanares (Argentina) Triassic --- -, (1928). Ein Cynodontier aus der Trias reptile fauna: 6. A chiniquodontid cynodont Brasiliens. Ibid., 1928, Abt. B, 250-270. with an incipient squamosal-dentary jaw artic­ ----, (1936). Die fossilen Reptilien des Siid- ulation. Ibid., 344, 1-18. 85

SCHMIDT, K. P., (1927). New reptilian genenc (Reptilia, Therapsida; Upper Permian). names. Copeia, 163, 58-59. Postilla, 126, 1-51. SEELEY, H. G., (1894a). Researches on the - --- , (1968b). Some new Upper Permian therio­ structure, organization, and classification of donts. p. 32-46. In Upper Paeoz oic and the fossil Reptilia. Pt. 9. Section 1. On the Amphibia and R eptilia from the Therosuchia. Phil. Trans. R. Soc., (B) 185, U.S.S.R. Moscow. (In Russian). 987-1 018. WATSON, D. M. S., (1913). On a new cynodont (1894). Researches on the structure, from the Stormberg. Geol. Mag., (5) 10, organization, and classification of the fossil 145-148. Reptilia. Pt. 9, Section 3. On Diademodon. - - --, (1917). A sketch classification of the Ibid., 1 029-1 041. pre-J urassic vertebrates. Proc. zool. ----, (1895a). Researches on the structure, Soc. Lond., 1917, 167-186. organization, and classification of the fossil ----, (1920). On the Cynodontia. Ann. Mag. Reptilia. Pt. 9, Section 4. On the Gompho­ nat. Hist., (9) 6, 506-524. dontia. Ibid., 186, 1-57. --- - , and ROMER, A. S., (1956). A classifi­ ----, (1895b). Researches on the structure, cation of therapsid reptiles. Bull Mus. compo organization, and classification of the fossil Zool., Harv., 114, 37-89. Reptilia. Pt. 9, Section 5. On the skeleton in WOODWARD, A. S., (1932). "Zittel's textbook of new Cynodontia from the Karroo rocks. Ibid., palaeontology", Vol. 2, Pt. 1, Macmillan and 59-148. Co., London, 464 p. ----, (1908). Additional evidence as to the YOUNG, C. C., (1940). Preliminary notes on the dentition and structure of the skull in the Mesozoic mammals of Lufeng, Yunnan. Bull. South African fossil reptile genus Diadem­ geol. Soc. China, 20, 93-111. odon. Proc. zool. Soc. Lond., 1908,611- 617. - - - - , (1947). Mammal-like reptiles from Lufeng, Yunnan, China. Proc. zool. Soc. Lond., 117, SIMPSON, G. G., (1928). A catalogue of the 537-597. Mesozoic Mammalia in the Geological Depart­ ----, (1959). Note on the first Cynodont from ment of the British Museum. British Museum Sinokannemeyeria- faunas in Shansi, China. (Natural History), London. 215 p. Vertebr. palasiat., 3, 124-131. TATARINOV, L. P., (1968a). Morphology and ----, (1961). On a new Cynodont from N.W. of the Northern Dvina cynodonts Shansi. Ibid., 1961, 109- 113.